This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: PR 6394
- From: "John David Anglin" <dave at hiauly1 dot hia dot nrc dot ca>
- To: dje at watson dot ibm dot com (David Edelsohn)
- Cc: geoffk at geoffk dot org, gcc at gcc dot gnu dot org
- Date: Tue, 30 Apr 2002 16:07:12 -0400 (EDT)
- Subject: Re: PR 6394
> >>>>> Geoff Keating writes:
>
> Geoff> Did you work out _why_ reg-alloc was chosing this class (and which
> Geoff> class it was choosing)? Often these problems are actually caused by
> Geoff> the machine description, for instance by not having the union of two
> Geoff> register classes available, and a new register allocator won't help
> Geoff> that.
>
> For the PowerPC case, DImode is allowed in FPRs. A loop was
> generated with a pseudo that was used as an FP value elsewhere. The
> register allocator could not be discouraged from using the FPR and could
> not split the variable across two different register classes.
DImode is also allowed in FPRs on the PA. The class used by global_alloc
for the pseudo was GENERAL_OR_FP_REGS. This was the first class selected
for the psuedo and a register %fr22 was selected from this class.
Dave
--
J. David Anglin dave.anglin@nrc.ca
National Research Council of Canada (613) 990-0752 (FAX: 952-6605)